生物操纵修复大型浅水湖泊生态系统的机理及数值模拟

Lake eutrofication and ecosystem degradation has been one of the key issues restrict regional development of society and economy. It is essential to explore a sustainable way in lake ecosystem restoration to construct aquatic ecological civilization in China. Fishery is a supporting industry in economic development in Lake Taihu area. However, the fast growth of fishery in Lake Taihu has great destructed its environment due to the “top down effects” of fish, the top predators, on lake ecosystems through energy flow in the food chains. The proposed study aims to reveal the responses of lake environment on fishery-based biomanipulation in large shallow lakes, to explore the method of fishery management on expediting of lake ecosystem restoration process, and to provide a double-win mode with the consideration of both environment improvement and fishery development. The outcomes from this study could provide a theoretical basis to the biomanipulation on lake ecosystem restoration. The major contents of this study includes: (1) feeding habits of dominant fish species and food web structure in Lake Taihu; (2) Lake Taihu ecosystem model construction; (3) impacts of biomanipulation on Lake Taihu ecosystem; and (4) exploration of a double-win mode with the consideration of both environment improvement and fishery development.

湖泊富营养化、湖泊生态系统退化已成为制约区域社会经济发展的关键因素之一，探索湖泊生态修复的长期可持续方法是水生态文明建设中急需解决的问题。太湖渔业是湖区经济发展的支柱产业，然而，由于鱼类位居湖泊生态系统中的最高营养级，经食物网自上而下影响着整个湖泊生态系统，使得太湖生态系统发生了巨大变化。本研究拟揭示兼顾渔业开发的生物操控对大型浅水湖泊水环境的影响机制，建立调整渔业结构以加速湖泊生态修复进程的方法，提出水环境改善和渔业发展双赢的优化管理模式，为生物操控方法修复湖泊水环境提供理论依据。具体研究内容包括：（1）太湖主要鱼类食性、食物网结构研究；（2）太湖生态系统模型构建；（3）生物操纵对太湖生态系统影响分析；（4）促进太湖水环境改善及渔业发展的生物操纵模式研究。

随着社会经济的快速发展，湖泊富营养化问题日趋严峻。探索湖泊生态修复的长期可持续方法是水生态文明建设中急需解决的问题。太湖渔业是湖区经济发展的支柱产业，然而，由于鱼类位居湖泊生态系统中的最高营养级，经食物网自上而下影响着整个湖泊生态系统，使得太湖生态系统发生了巨大变化。本项目选取最典型的大型浅水湖泊-太湖为研究对象，通过历史资料收集以及野外调查，深入分析了太湖鱼类种群变化趋势及其主要影响因素；利用稳定同位素与胃肠含物相结合的方法对采集的鱼类样品食性进行分析研究，建立了太湖鱼类食物网。构建了太湖水质-植物及浮游动植物-鱼类-沉积物等生态模型，通过原位实验、实验室模拟及数值模拟方法，提出了生物操纵改善太湖湖泊水环境质量的基本方法。